Medical appliances, particularly operating room equipment, must be kept sterile. Many surgical instruments are taken away from the operating room between operations to be cleaned and sterilized. However large or sensitive instruments, equipment and operating room fixtures cannot be easily moved. For example, devices such as surgical lamps cannot be removed from the operating room between operations. Such appliances are therefore cleaned and sterilized in situ. The handles of the lamps are of special concern because they are frequently handled during operations. Such lamp handles typically have associated cylindrical projections with a conical base connecting it to the lamp assembly. The conical base provides insulation from the heat generated by the lamp, a resting point for the hand for increased leverage when adjusting the position of the lamp and a barrier to prevent the hand from sliding beyond the handle exposing un sterilized parts.
In the past, surgical lamps have been sterilized between operations by spraying an antiseptic solution. This procedure however is far from sufficient. Nowadays the use of reusable detachable handles is commonplace. Such handles can be sterilized in an autoclave before each surgical procedure. The disadvantages of such a practice are the operational inconvenience of dismantling, sterilizing and reassembly and the considerably high rate of wearing out of the handles, which are typically made of plastics, as a result of the high temperatures involved.
U.S. Pat. No. 4,605,124 discloses disposable covers for handles of lighting fixtures made of a flexible plastic, latex or rubber. The covers are molded to closely conform with the shape of a handle. An adaptation kit consisting of a substitute handle and attaching means to the lamp assembly is provided in such cases in which the dimensions of the original handle do permit fitting of the disposable cover. The disposable cover consists of a grip and a flange. The flange is flat, or conically shaped fitted to cover the handle base. The cover is attached to the handle either by means of the flange, its rim, or detent means and or snap ring attaching the cover to the grip of the handle. The flange rim is preferably slightly undersized relative to the handle base providing a snap over fit. An improved attachment of the cover is achieved by adhering the flange to the handle base. The main disadvantage of using such covers is that often, there is a need to replace the original lamp handle. The substituting handle is made to fit the disposable handle cover. This process is expensive and necessitates replacement of a well-designed handle by a lesser grade design. Another difficulty associated with such covers is that they are typically held in place with adhesives. Therefore it must be replaced after repeated use due to a buildup of adhesive residue.
U.S. Pat. No. 4,976,299 discloses a sterile disposable plastic cover for a handle of an operating room lighting fixture. The cover includes a hollow member closed at one end and open at its other end. Around the open end is attached a hand guard. The open end is partially restricted with a retention member permitting the handle of the lighting fixture to extend through the open end of the hollow member and holding it in place. The retention member is preferably a disc having intersecting slits, which define an opening smaller than the handle and the opened end of the hollow member. The cover is attached to the handle by friction exerted by the retention member being pressed against the surface of the handle. This solution has its drawbacks for example, in order to accommodate the large variety of dimensions of handles available, there is a need for several different sterile disposable plastic covers having different lengths and bore sizes. Although the retention elements formed intersecting slits of the retention member are flexible and therefore can accommodate a range of handle sizes, the component of the force which is normal to the handle surface decreases as the stripes are more extremely bent. Therefore several different bore radii and corresponding lengths of the intersecting slits are required to provide a firm attachment of a disposable cover to a variety of available handles. Furthermore the hollow member has to be secured to the light handle lest it should fall off. Employing a cover having a too long hollow member might interfere with the operation of the operating team while adjusting the light fixture during the procedure. All these factors are considered when buying or maintaining the appliances in a hospital.